Ganoderma resinaceum Boud. is a large, annual, laccate (varnished) bracket fungus of broadleaf trees, especially oak, in Europe and beyond. It forms broad, sessile, reddish-brown to mahogany shelves with a shiny, resinous crust (the 'resin' that gives the name). It causes a white rot of the heartwood and roots of living trees and is a significant tree-safety concern in parks.
On trunks and root bases of living or dead broadleaf trees, especially Quercus; also Salix, Fraxinus, Fagus.
Distribution
Europe and the Mediterranean; also reported from North Africa, Asia, Australia and the Americas.
Characteristics
Cap: 10-50 cm, sessile, fan- to kidney-shaped, laccate reddish-brown with a pale yellowish-white growing margin; crust resinous (oozes resin; widely reported to soften when heated). Pores: white to cream (often pale yellow when young), bruising brown. Flesh: soft-corky, light brown. Spores: brown, truncate-ellipsoid, double-walled, about 9-11 x 5-7 um.
